import React,{useState} from 'react'

// 
const App = ()=>{
    let [count,setCount] = useState(0)
    return ( <div>
            <button onClick={()=> setCount(count+1) } >++</button>
            <Show count={count}></Show>
        </div>)
}

const Show = ({count})=>{
    console.log('update')
    return (
        <div>{0}</div>
    )
}

export default App

